Japanese font specification is incorrect.

Nobody has claimed this yet.

Japanese fonts could not be displayed correctly when specified in PointAnnotation.
Specifically, Japanese characters (あ-ん, 漢字 etc.) are rendered in the default font, while alphabetic and numeric characters (A-z, 0-9) are rendered in the specified font.

Now using mapbox_maps_flutter: ^0.4.1

Below doctor.
```
flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.7.3, on macOS 12.6.1 21G217 darwin-arm64, locale ja-JP)
[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 14.2)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2020.3)
[✓] VS Code (version 1.75.1)
[✓] Connected device (3 available)
! Error: (null) needs to connect to determine its availability. Check the connection between the device and its
companion iPhone, and the connection between the iPhone and Xcode. Both devices may also need to be restarted and
unlocked. (code 1)
[✓] HTTP Host Availability

• No issues found!
```

Thank you.

Start at the PointAnnotation font configuration in mapbox_maps_flutter and reproduce the issue with Japanese and alphabetic characters using version 0.4.1. Compare rendering on the reported Flutter Android and iOS environments. Done means Japanese characters render with the specified font instead of falling back to the default font.

Written by the indexing model from the issue text.